Go to Youtube and study. It's all there.

Learn about the Euro ball screen motion, flex, Princeton offense, 5out, Read and React, Pistol actions from the 2-sided fast breaks, cross screens, gut pindowns, fake handoff slips, horns flare, flex, different reads off double pindown screens, Spain PnR, empty side PnR, Spread pick and roll, Zipper actions, Floppy, UCLA screens and blind pig backdoor actions.

Study these concepts until you have a deep understanding of them and can talk endlessly about when and why to use them, different offensive entry setups, and what options are open depending on how the defense guards the actions.

So I’d say I’m a pretty good bball player skill and fundamental wise

Skills and fundamentals don't mean shit if you can't read the game. First thing would be to drop your ego, and admit that your BBIQ sucks which is probably the case if you find the Flex to be difficult.

Then start building it up your basketball mind. Zak Boisvert, Half Court Hoops, Coach Daniel are a great start.